Academic achievement of low birthweight children at age 11: The role of cognitive abilities at school entry

We examine the extent to which deficits in academic achievement in low birthweight (LBW) children at age I I are explained by deficits in cognitive abilities at school entry. Data come from a longitudinal study of a stratified sample of LBW and normal birthweight (NBW) children from an innercity and middle class suburbs in the Detroit area. Woodcock-Johnson Psychoeducational Battery-Revised was used to measure reading and math at age 11. WISC-R and specific neuropsychologic tests were administered at age 6. On reading, the LBW-NBW difference was -3.6 points (SE = 1.2). The difference was explained almost entirely by IQ at age 6. On math, the LBW-NBW difference was -6.1 points (SE = 1.1). The difference on math was trivial and not significant, when IQ and neuropsychological tests at age 6 were controlled. Level of LBW was unrelated to reading, but it had a gradient relationship with math, with birthweight <1,500 g associated with a greater deficit than heavier LBW. The results imply that most of the LBW-NBW gap in academic achievement at age I I could be eliminated by eliminating differences in cognitive abilities at age 6. Interventions to improve academic performance of LBW children should focus on the preschool years.